This application is based on Patent Application No. 2000-277331 filed Sep. 12, 2000 in Japan, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates generally to an ink supply recovery system and an ink supply recovery method performing ink supply and recovery of suction of the ink using a pit-in ink supply system and to an ink-jet printing apparatus having the ink supply recovery system. More particularly, the invention relates to an improvement for down-sizing of an ink supply recovery system and an ink-jet printing apparatus having the ink supply recovery system. Also, the invention relates to an image pick-up device having a recording mechanism including the down-sized ink supply recovery system.
2. Description of the Related Art
As an ink-jet printing apparatus, conventionally, there is a so-called serial scanning system having a movable carriage in a main scanning direction, on which a printing head as printing means and an ink tank as an ink container are exchangeably mounted. This printing system sequentially performs printing of image on a printing medium by repeating primary scanning of the carriage mounting the printing head and the ink tank and auxiliary scanning of the printing medium.
Considering realization of an ultra-compact printer suitable for PDAs or cameras, size of the carriage per se becomes small. Therefore, an ink storage capacity of the ink tank to be mounted on such a small carriage inherently becomes quite small.
When the capacity of the ink tank on the carriage is extremely small as set forth above, frequency of exchanging of the ink tank becomes high or to potentially cause necessity of exchanging of the ink tank during printing operation.
Therefore, in order to solve such problems, there has been proposed an ink supply system, in which whenever the carriage is placed at a predetermined stand-by position, an ink is supplied from a main tank provided independently of the carriage to a sub-tank on the carriage at an appropriate timing. Such ink supply system will be referred hereinafter as xe2x80x9cpit-in ink supply systemxe2x80x9d for convenience of disclosure.
With such pit-in ink supply system, for example, at every occurrence of printing of one sheet of printing medium, the carriage is placed at the predetermined stand-by state to connect the sub-tank on the carriage with the main tank at an appropriate timing for supplying ink from the main tank to the sub-tank in connected condition. Thus, the problem of ink storage capacity of the sub-tank on the carriage can be solved.
On the other hand, in the foregoing pit-in ink supply system, an ink absorbing body, such as sponge or the like, is arranged in the sub-tank and a resupply of ink is carried out by introducing a negative pressure into the sub-tank through an air intake opening thereby introducing the ink from the main tank into the sub-tank through an ink introducing.
On the other hand, in the ink-jet printing system, when air penetrates into the inside of nozzles of the printing head and viscosity of the ink is increased by evaporation, or in other reason, the nozzles cause ink ejection failure to make it impossible to eject ink droplet from the nozzles. Therefore, a capping member covering a face of the printing head and suction means for sucking the ink from the nozzles of the printing head are provided for sucking and removing the ink not contributing for printing the image, from the tip end of the nozzles at certain timing.
In such pit-in ink supply system, a construction for suction of air for resupplying ink, suction recovery of the ink from the printing head and further recovery of ink supply for discharging of the sucked ink, become necessary. A portion of such construction occupies large proportion with respect to the overall printer.
Therefore, as set forth above, in order to realize an ultra-compact ink-jet printer adapted to compact electronic devices, such as those for PDAs, cameras or the like, it is important how to make the structural portion for recovering ink supply compact.
Particularly, in this case, a suction pump can be a bottle neck in down-sizing since such suction pump is required to perform suction of air and suction of ink.
Moreover, in the pit-in ink supply system of the printer for such compact electronic devices, it is expected to perform resupply of the ink and suction recovery every time of printing on one printing medium, normally. Therefore, it is also important how to complete a series of processes for ink supply and suction recovery efficiently in a short period.
The present invention has been worked out in view of the problems in the prior art as set forth above. Therefore, it is an object of the present invention to provide an ink supply recovery system which can realize down-sizing and can efficiently perform a series of supply recovery.
In a first aspect of the present invention, there is provided an ink supply recovery system comprising:
a pack body including a main tank connected to an ink joint and storing an ink, and a waste ink receptacle means for receiving waste ink, the pack body being detachably mounted on a printer body;
on the printer body,
a sub-tank mounted on a carriage, the sub-tank having a negative pressure introducing portion arranged with a porous membrane and an ink intake portion connectable with the ink joint, and taking ink into inside from the ink intake portion by a negative pressure introduced from the negative pressure introducing portion;
a cap for capping ink ejection openings of a printing head ejecting the ink supplied from the sub-tank;
a cylinder pump having
a reciprocally movable piston,
a cylinder body having an air suction chamber, defined on one side of the piston, connectable with the negative pressure introducing portion and an ink suction chamber, defined on the other side of the piston, connected with the cap via an input port and connectable with the waste ink receptacle means via an output port, and
port switching means for switching the input port and the output port open and close associating with movement of the piston; and
drive control means for controlling movement of the piston of the cylinder pump, switching of the port switching means, contacting and releasing of the cap relative to the printing head, contacting and releasing of the ink joint relative to the ink intake portion of the sub-tank, and contacting and releasing between the negative pressure introducing portion of the sub-tank and the air suction chamber.
Here, the drive control means may include means for contacting the cap with the printing head, jointing the ink joint with the ink intake portion of the sub-tank, connecting the negative pressure introducing portion of the sub-tank with the air suction chamber, closing the input port and opening the output port by the port switching means, and in this condition, moving the piston for reducing pressure in the air suction chamber and pressurizing the ink suction chamber so as to perform resupplying of ink from the main tank to the sub-tank and discharging of ink from the ink suction chamber to the waste ink receptacle means.
The drive control means may include means for contacting the cap with the printing head, releasing the ink joint from the ink intake portion of the sub-tank, disconnecting the negative pressure introducing portion of the sub-tank with the air suction chamber, opening the input port and closing the output port by the port switching means, and in this condition, moving the piston for pressurizing the air suction chamber and reducing pressure in the ink suction chamber so as to perform a suction recovery operation for sucking ink from ink ejection openings of the printing head.
The drive control means may include means for opening the atmosphere communication valve after a suction recovery operation of ink, and in this condition, moving the piston for pressurizing the air suction chamber and reducing pressure in the ink suction chamber so as to perform an idle suction recovery operation.
The pack body may include a wiper which can be projected and retracted for wiping of an ink ejection opening forming surface of the printing head, and the drive control means may include means for performing wiping by moving the carriage in a condition where the wiper is projected.
The ink intake portion may be a needle form formed with a through hole.
The piston rod of the piston of the cylinder pump may extend outside of a cylinder body through the ink suction chamber.
The port switching means may comprise a switching valve disposed within the ink suction chamber.
The printing medium may be incorporated in the pack body.
The printing head may eject ink by applying thermal energy to ink.
In a second aspect of the present invention, there is provided an ink supply recovery method comprising the steps of:
loading a pack body including a main tank connected to an ink joint and storing ink and a waste ink receptacle means on a printer main body, the printer main body including
a sub-tank which is mounted on a carriage, has a negative pressure introducing portion arranged with a porous membrane and an ink intake portion, and supplies ink to a printing head,
a cap for capping ink ejection openings of the printing head, and
a cylinder pump including
a reciprocally movable piston,
a cylinder body having an air suction chamber defined on one side of the piston and connectable with the negative pressure introducing portion and an ink suction chamber defined on the other side of the piston, connected with the cap via an input port and connectable with the waste ink receptacle means via an output port, and port switching means for performing switching open and close of the input port and the output port associating with movement of the piston;
then contacting the cap on the printing head;
jointing the ink joint to the ink intake portion of the sub-tank;
interconnecting the negative pressure introducing portion of the sub-tank and the air suction chamber;
closing the input port and opening the output port by the port switching means; and in this condition
moving the piston for reducing pressure in the air suction chamber and pressurizing the ink suction chamber for resupplying ink from the main tank to the sub-tank and discharging ink from the ink suction chamber to the waste ink receptacle means.
In a third aspect of the present invention, there is provided an ink supply recovery method comprising the steps of:
loading a pack body including a main tank connected to an ink joint and storing ink and a waste ink receptacle means on a printer main body,
the printer main body including
a sub-tank which is mounted on a carriage, has a negative pressure introducing portion arranged with a porous membrane and an ink intake portion, and supplies ink to a printing head,
a cap for capping ink ejection openings of the printing head, and
a cylinder pump including
a reciprocally movable piston,
a cylinder body having an air suction chamber defined on one side of the piston and connectable with the negative pressure introducing portion and an ink suction chamber defined on the other side of the piston, connected with the cap via an input port and connectable with the waste ink receptacle means via an output port, and port switching means for performing switching open and close of the input port and the output port associating with movement of the piston;
in this condition, contacting the cap on the printing head;
releasing the ink joint from the ink intake portion of the sub-tank;
disconnecting the negative pressure introducing portion of the sub-tank with the air suction chamber;
opening the input port and closing the output port by the port switching means; and
in this condition, moving the piston for pressurizing the air suction chamber and reducing pressure in the ink suction chamber for performing a suction recovery operation for sucking ink from the ink ejection openings of the printing head.
Here, the printer main body may further include an atmospheric communication valve for opening and closing an atmosphere communication opening formed in the cap, the method may further comprises the steps of:
opening the atmosphere communication valve after the suction recovery operation of the ink; and in this condition, moving the piston for pressurizing the air suction chamber and reducing pressure in the ink suction chamber so as to perform an idle suction recovery operation.
Here, the pack body may further include a wiper, which is projectable or retractable, for wiping an ink ejection openings forming surface of the printing head, the method may further comprises a step of;
performing wiping by moving the carriage in the condition where the wiper is projected.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.